1. Field of the Invention
This invention relates to a stopping device used for a bellows focusing attachment or a close photography ring to stop the phototaking lens at an optional position which has been at its fully opened position as mounted.
2. Description of the Prior Art
Heretofore when a bellows focusing attachment or close photography ring is mounted on a camera of the through the lens photometry type, the stop is stepped at a predetermined position; that is, the photometry has been made by the so-called stopping photometry. On the other hand, when using a lens of the type of which the stop is at its fully opened position when mounted, observing the depth of field is accomplished by stopping the lens stop by a simple operation. When the bellows focusing attachment and the close photography ring equipped with a specific interlocking member to interlock the stopping device of the camera and the stop lever of the lens, or the bellows focusing attachment and the close photography ring equipped with the lens provided with the stopping means is used, it is possible to make the stopping operation optionally. However, the operability is poor. In known devices other than the aforementioned two conventional devices, it is necessary to include a mechanism to move the stop lever of the lens. Such mechanism is generally in the form of an intermediate ring inserted between the bellows and the lens. When focusing is necessary, this intermediate ring moves a member connected with the stop of the lens to the fully opened stop position and locks it at this position, and a lock releasing member which is quite complex in structure has been needed.
In case of an intermediate ring which does not have an associated lock releasing member, it is not possible to stop unless the shutter release member, such as a double cable release, is operated. However, if the shutter is charged, then the shutter is released and the film is exposed to light. Further, the shutter release member is constructed to operate the stopping before the shutter is released. Thus, it may be possible to cease the release operation at the position of the stopping just before the shutter is released and retain it at this position. However, if there is the slightest deviation from such position, it is impossible to determine the exposure and the selection of the stop and shutter speed becomes inconvenient.